package com.cx.base.day12_framework.map;

import java.util.Map;
import java.util.TreeMap;

/**
 * @Author: robert.song
 * @Date: Created in 2022/5/27
 */
public class TreeMapTest {

    public static void main(String[] args) {

        Map treemap = new TreeMap();
        treemap.put("key1", "val1");
        treemap.put("key1", "val1");
        treemap.put("key1", "val1");
        treemap.put("key1", "val1");
        treemap.put("key1", "val1");
//        不允许key为null
        System.out.println(treemap.put("key1", null));
        ;
        System.out.println(treemap.toString());
    }
}
